The chief executives of five major oil companies were asked Wednesday to clarify their recent Senate testimony about the companies' involvement in Vice President Dick Cheney's energy task force four years ago.

Sens. Pete Domenici, R-N.M., and Jeff Bingaman, D-N.M., made the request in letters to the executives after a published report said officials from four of the companies visited the White House complex in early 2001 to discuss energy issues with task force staff members.

The White House has refused to disclose contacts with industry representatives concerning the task force deliberations.

When Sen. Frank Lautenberg, D-N.J., asked last week during a hearing on oil industry profits whether any of the companies' representatives had participated in the task force, four of the executives said they did not and the fifth said he did not know.

The oil executives weren't put under oath at the hearing, but it is still a crime to lie to Congress, reports CBS News correspondent Bob Fuss. Lautenberg wants the Justice Department to look into it.

"It's bad enough to hide the truth to the American people, but it's illegal to make false statements to the Congress, whether you've raised your right hand or you haven't," Lautenberg said.

The Washington Post, citing White House documents, reported Wednesday that representatives from four of the companies had visited the White House complex and met with Cheney task force officials in early 2001.

Domenici, chairman of the Energy and Natural Resources Committee, said he sent a letter to the oil company executives seeking clarifications that would resolve any "apparent inconsistencies" in their testimony. He was joined in the letter by Bingaman, the energy panel's ranking Democrat.

Sen. Maria Cantwell, D-Wash., and five other Democrats asked Domenici to recall the executives and require them to testify under oath this time.

"We deserve truthful answers from the oil company executives. This is an issue that is impacting our economy," said Cantwell.

The executives who testified last week on oil industry profits were Lee Raymond, chairman of Exxon Mobil Corp.; David O'Reilly, chairman of Chevron Corp.; James Mulva, chairman of ConocoPhillips; John Hofmeister, chairman of Shell Oil Co.; and Ross Pillari, chairman of BP America Inc.

Chevron was not included in the documents cited by the Post. Don Campbell, a Chevron spokesman, said the company did not participate in Cheney's task force but added that its Washington office has had ongoing discussions about energy policy with administration officials and members of Congress.

Pillari said he did not know whether any BP America officials participated because he wasn't at the company at the time. While not commenting specifically about the Cheney task force, BP America spokesman Ronnie Chappell said Wednesday that BP America representatives "routinely meet with government officials."

Exxon Mobil said in a statement that Raymond "correctly confirmed in the recent Senate hearings that Exxon Mobil has not been a participant on the task force and did not meet with the task force to discuss the provisions of the energy policy."